It's not that hard. it just costs money. drop the tail of the zf6 down a hair. maybe push up on the tunnel a hair. it will clear.

The output on the 6 is bigger than the e4od, 4r100 and zf5. So not all SD cases will work. Has to be one from a 6 speed SD. This is 7.3 trucks. IDK about 6.0s or what the output is on 5r110s

 

Looks like I will need to find a SD ZF6 tranfer case.......

But, it will be worth it in the end..........

 

Thanks, I missed the transfer case info, I appreciate it.

The 5.76 first gear is what I'm after, the 4.14 and 3.55's sux........

And a 5 mph higher speed in overdrive at 2000 rpm will be nice too ! ! !

Also I have twice, towing heavy in overdrive, had the ZF5 get hot and not want to shift when I got off the interstate.

 

Don't quote me on it, but i recall reading that a ZF6 will fit in the OBS trans tunnel with a body lift.

Don't take my word for it though, do some googling if that becomes the deciding factor.

 

I thought I read that with the manual shift tunnel cover it would fit, just the automatic tunnel wouldn't clear.

I had rather not do a cab lift.

May have to do some precision BFH mods to the floor.

 

I have no doubts that with a big enough hammer you'll be able to clear a ZF6.

You just can't do a writeup on something and have step 14 be "Beat trans tunnel with massive hammer until trans fit" as some people aren't into the BFH life.

 

BFH life haha.

dropping the tail down should get it close to where it just touches, or rubs, and just push up on the floor with a jack or something to make it clear. shouldn't need a BFH, and it just a little bit, nothing that should be noticeable looking at from inside or underneath. I forget for sure though what was done one my buddy's truck we put a zf6 in.

 

Anyone doing DIY at this level should be willing to use the BFH when appropriate.

Dropping the tail would change the driveline angle, no? So you'd want to adjust the angle at the diff to match?

 

Doesn't this change the angles of all the oil pick-ups too (engine, tranny, etc)? ...along with the drain back ports...




That would bother me....

 

I suppose it would a slight amount. if it was an issue, putting different pitched wedges on the rear axle could re align the drive line angles. but depending on the truck configuration, it probably wont matter. everything other than a rclb has 2 piece shaft, don't they?

The pick ups should be covered in oil even at extreme angles, a few degrees shouldn't matter. Plus this is only the case when on level ground. Hills, loaded bed, or trailer, plow, lift kits, worn out springs would all affect how the engine sits. I think it will be fine

 

AFAIK all SC and CC trucks have two-piece rear driveshafts. But that has no bearing (no pun intended...) on the driveline angles. The output of the t-case and the input of the diff should be parallel.

 

As far as driveshaft lengths are concerned it's totally possible to cut and shorten a driveshaft yourself if you have a welder and a dial indicator.

I've had pretty good success shortening driveshafts and then using a dial indicator to get it true and then slowly working my way around it tacking it and checking it up to make sure it holds true.

Probably done four or so that way and never once have had any vibration issues.

 

7.3 6 speed trans are very rare to say the least.
If you are doing the swap, you'll also need a 7.3 ZF 6 speed t-case, not just ANY Super Duty 6 speed t-case, but a 7.3 6 speed t-case. The 6.0 6 speed trans and t-cases are different and won't just swap in place.

I like Bill's option the best, a Hybrid gets the best all around gearing. The only positive thing about doing a 6 speed swap in an OBS, if there is one, is to brag that you did the swap. I can't see any other reason to do it.

 

I wont have any more into the swap in my F-sd than what some ppl have in a zf5 swap. not a big deal there. The the gain of an extra gear is nice, I honestly cant stand my zf5 in my 350, but i recently sold a 460 zf to someone to turn their 7.3 zf to a 4x4, I drove that truck and it was a lot nicer than mine. Reverse is up and to the left, nice for going back and forth. I have the 05+ axles, might as well go zf6. already need custom shafts anyways. Just something I wanted to do, a project iv been accumulating parts for over a few years.

What is difference about 6.0 zf6 t cases, if you know? and what about zf6 t cases off later gas trucks? same as the 6.0 ones?

 

No idea on gas truck stuff, not a clue at all.
The 7.3 and 6.0 t-cases have different inputs, and the 6 spd and auto trans t-cases have different inputs again.
So you have to match standard vs auto trans, and 7.3 vs 6.0 engine to get the correct t-case.